This project concerns itself with two major areas of clinical research endeavor: l) a diazepam maintenance study performed with a group of anxious outpatients, and 2) the continuation of a set of functions involving the selection and training of a group of physicians in private practice, the Private Practice Research Group (PPRG). In addition to training members of the PPRG to assess the response to double blind drug trials of patients, appropriately chosen from their practices, it is necessary to continuously monitor their functioning and to recruit and train new group members, as established members leave the group. The diazepam maintenance trial studies the effect of periods of diazepam treatment of varying length (i.e., 6 weeks, 14 weeks and 22 weeks) on treatment outcome, as well as on the recurrence of stymptomatology or occurrence of withdrawal reactions once patients are switched to placebo under double blind conditions. A broadly-based standardized battery of doctor and patient rating scales will be used pre-treatment and at regular intervals during the study period. For each patient, blood samples will be drawn five times during a six week acute treatment phase and four times during the 18 week maintenance phase which follows. The relationship between diazepam and desmethyldiazepam plasma levels and clinical outcome, dosage intake, and other relevant parameters will be investigated. A sufficient number of patients will be started in the acute phase of the study to assure that at least 150 patients will complete six weeks of diazepam treatment and enter the maintenance treatment phase. This is the first controlled anxiety maintenance study of a benzodiazepine (diazepam). It should provide much needed information concerning the management of anxious patients on long term benzodiazepine treatment.